The present invention relates to a method for obtaining a preparation of β-amylases from the soluble fraction of starch plants, characterized in that the soluble fraction of starch plants is selected from the group consisting of the soluble fractions of wheat, pea, broad bean, horse bean, rice, barley, rye, buckwheat, potato and sweet potato, and preferably of wheat and barley, a clarification of said soluble fractions is carried out in such a way as to remove therefrom the insoluble substances and the colloids and, optionally, an ultrafiltration of said clarified soluble fractions is carried out in such a way as to obtain an ultrafiltration retentate containing the concentrated β-amylase and an ultrafiltration permeate, said ultrafiltration retentate containing the concentrated β-amylase is diafiltered and the resulting β-amylase is recovered.
